Electromagnetic-type pump

ABSTRACT

An electromagnetically driven diaphragm pump ( 100 ) includes a diaphragm ( 142 ), a first center disk ( 150 ) and a second center disk ( 160 ), and an oscillator ( 130 ). The first center disk ( 150 ) has a circular-ring shaped first disk contact surface ( 151   a ) that is disposed opposing an outer surface ( 144 ) of the diaphragm ( 142 ) and that makes contact with the outer surface ( 144 ) when the oscillator ( 130 ) is in the neutral position. The second center disk ( 160 ) has a circular-ring shaped second disk contact surface ( 161   a ) that is disposed opposing an inner surface ( 145 ) of the diaphragm ( 142 ), and makes contact with the inner surface ( 145 ) when the oscillator ( 130 ) is in the neutral position. The second center disk ( 160 ) has an outer diameter (D 2   b ) set in the range of 1.05-1.30 times an outer diameter (D 1 b) of the first disk contact surface ( 151   a ).

TECHNICAL FIELD

The present invention relates to an electromagnetic-type pump.

BACKGROUND ART

An electromagnetic-type pump is a pump configured to suck in and discharge a fluid in accordance with linearly reciprocating oscillation of an oscillator caused by an electromagnetic coil. Up to now, a well-known example of this type of electromagnetic-type pump is one that is structured such that a central area of a diaphragm having elastic properties is sandwiched, from both surfaces, by two center disks, and the oscillator is coupled to these two center disks. For example, this type of electromagnetic-type pump is disclosed in Patent Document 1 mentioned below.

PRIOR ART LITERATURE Patent Documents

Patent Document 1

Japanese Laid-open Patent Publication 2000-170660

Patent Document 2

Japanese Laid-open Utility Model Publication H6-53858

SUMMARY OF THE INVENTION

The electromagnetic-type pump disclosed in the above-mentioned Patent Document 1 comprises, as the two center disks, a first center disk, which is located on an outer side of the pump, and a second center disk, which is located on an inner side of the pump. The electromagnetic-type pump is configured such that a diameter (clamping diameter) of an area in which the first center disk makes contact with the diaphragm when the oscillator is in a neutral position and a diameter (clamping diameter) of an area in which the second center disk makes contact with the diaphragm when the oscillator is in the neutral position are identical.

Consequently, during reciprocating oscillation in an intake direction and a discharge direction of the oscillator, both an outer surface and an inner surface of the diaphragm bend at the same location in the radial direction. In the case of an electromagnetic-type pump having the present configuration, there is a concern that the service life of the diaphragm will decrease because a local load concentration arises in the diaphragm owing to the reciprocating movement of the oscillator.

Accordingly, to prevent a decrease in the service life of the diaphragm, it is conceivable to refer to the apparatus disclosed in the above-mentioned Patent Document 2. This apparatus is configured such that the position in the radial direction of the bent part on the outer surface of the diaphragm (hereinbelow, also called a “first radial-direction position”) and the position in the radial direction of the bent part on the inner surface of the diaphragm (hereinbelow, also called a “second radial-direction position”) differ from one another. Moreover, in addition to preventing a decrease in the service life of the diaphragm, there is also a demand to design the electromagnetic-type pump more compactly. To meet such a demand, it is insufficient to merely make the first radial-direction position and the second radial-direction position of the diaphragm different.

Problems to be Solved by the Invention

Accordingly, the present invention was conceived considering the above-mentioned points, and one object of the present invention is to provide an effective technique that, in an electromagnetic-type pump comprising a diaphragm coupled to an electromagnetically driven oscillator, prolongs the service life of the diaphragm and achieves compactness of the pump.

Means for Solving the Problems

To achieve the above-mentioned object, an electromagnetic-type pump (100) according to the present invention comprises a diaphragm (142), a first center disk (150) and a center disk (160), an oscillator (130), and a valve case (103). The diaphragm (142) is a discoidal member that is composed of an elastic material. The first center disk (150) and the second center disk (160) are both discoidal and concentric with the diaphragm (142) and are fixed to one another in the state in which they sandwich—from both surfaces in a sheet-thickness direction—a central area of the diaphragm (142). The oscillator (130) is coupled to at least one of the first center disk (150) and the second center disk (160) and reciprocatively oscillates in an intake direction and a discharge direction about a neutral position. The valve case (103), on an opposite side of the oscillator (130), sandwiching the diaphragm (142), has a compression chamber (104) for sucking in a fluid during movement in the intake direction of the oscillator (130) and for compressing that fluid during movement in the discharge direction of the oscillator (130).

The first center disk (150) has a circular-ring shaped first disk contact surface (151 a) that is disposed opposing an outer surface (144)—of the two surfaces of the diaphragm (142)—located on the compression-chamber (104) side of the valve case (103) and that makes contact with the outer surface (144) when the oscillator (130) is in the neutral position. The second center disk (160) has a circular-ring shaped second disk contact surface (161 a) that is disposed opposing an inner surface (145)—of the two surfaces of the diaphragm (142)—located on the oscillator (130) side, makes contact with the inner surface (145) when the oscillator (130) is in the neutral position, and has an outer diameter (D2 b) set in the range of 1.05-1.30 times an outer diameter (D1 b) of the first disk contact surface (151 a). During reciprocating oscillation in the intake direction and the discharge direction of the oscillator (130), the diaphragm (142) centrally bends at a contact part (144 a) within the outer surface (144), with respect to the outer circumference (P1) of the first disk contact surface (151 a) of the first center disk (150), and centrally bends at a contact part (145 a) within the outer surface (145), with respect to the outer circumference (P2) of the second disk contact surface (161 a) of the second center disk (160).

According to the present configuration, because the outer diameter of the first disk contact surface of the first center disk and the outer diameter of the second disk contact surface of the second center disk differ, the position in the radial direction of the bent part of the outer surface of the diaphragm and the position in the radial direction of the bent part of the inner surface differ from one another during reciprocating oscillation in the intake direction and the discharge direction the oscillator. Accordingly, it is possible to prevent a local load concentration from arising on the diaphragm during the reciprocating movement of the oscillator, and therefore the service life of the diaphragm can be prolonged. Furthermore, by embodying the relative relationship between the outer diameter of the first disk contact surface and the outer diameter of the second disk contact surface according the above-mentioned numerical values, the first center disk located on the compression chamber side of the valve case can be made smaller than the second center disk located on the oscillator side and it also becomes possible to keep the size of the second center disk small.

In the electromagnetic-type pump (100) having the above-mentioned configuration, the first center disk (150) preferably has a first disk curved surface (152 a) and the second center disk (160) preferably has a second disk curved surface (162 a). The first disk curved surface (152 a) extends from the outer circumference of the first disk contact surface (151 a) while curving outward in the disk-radial direction with a prescribed radius of curvature (R) and is formed in a ring shape in the disk circumferential direction. The second disk curved surface (162 a) extends from the outer circumference of the second disk contact surface (161 a) while curving outward in the disk-radial direction with the same radius of curvature (R) as that of the first disk curved surface (152 a) and is formed in a ring shape in the disk circumferential direction.

According to the present configuration, in accordance with the reciprocating oscillation in the intake direction and the discharge direction of the oscillator, although the outer surface of the diaphragm makes contact with a first disk curved surface of the first center disk, when the inner surface of the diaphragm makes contact with a second disk curved surface of the second center disk, it is possible to prevent the diaphragm from bending locally. Furthermore, the deflection of the diaphragm at this time is the same, i.e., is balanced, on the first disk curved surface side and the second disk curved surface side. As a result, it is possible to prevent fatigue of the diaphragm from being biased toward either the outer surface or the inner surface. In addition, the first center disk, which has the first disk contact surface and the first disk curved surface, can be made comparatively smaller than the second center disk, which has the second disk contact surface and the second disk curved surface, and it becomes possible also to keep the size of the second center disk small.

It is noted that, in the above-mentioned explanation, to assist with the understanding of the invention, symbols used in the embodiments have been appended, in parentheses, to structural elements of the invention such that the symbols correspond to the embodiments; however, the configuration requirements of the invention are not limited to the embodiments in which the symbols are defined.

Effects of the Invention

According to the present invention as described above, in an electromagnetic-type pump comprising a diaphragm coupled to an electromagnetically driven oscillator, it becomes possible to prolong the service life of the diaphragm and to achieve compactness of the pump.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing that schematically shows the structure of an electromagnetic-type pump of the present embodiment.

FIG. 2 is a drawing that shows an aspect during an intake operation of the electromagnetic-type pump in FIG. 1.

FIG. 3 is a drawing that shows an aspect during a discharge operation of the electromagnetic-type pump in FIG. 1.

FIG. 4 is a drawing, viewed from a drive-chamber side, of a diaphragm part of the electromagnetic-type pump in FIG. 1.

FIG. 5 is a drawing that shows a cross-sectional structure taken along line A-A of the diaphragm part in FIG. 4.

FIG. 6 is a drawing that shows an aspect during an intake operation of the diaphragm part in FIG. 5.

FIG. 7 is a drawing that shows an aspect during a discharge operation of the diaphragm part in FIG. 5.

MODE(S) FOR CARRYING OUT THE INVENTION

One embodiment of an electromagnetic-type pump of the present invention is explained below, with reference to the drawings. This electromagnetic-type pump is typically used as an air pump for supplying air to water to be treated in a septic tank or an air pump (also called a “blower”) for supplying drive air to an air-lift pump for transferring water to be treated in a septic tank. It is noted that, in the drawings for explaining the electromagnetic-type pump, an intake-movement direction (a first direction) of an oscillator driven by electromagnetic forces is indicated by arrow X1, and a discharge-movement direction (a second direction that is a direction opposite that of the first direction) of the oscillator is indicated by arrow X2.

As shown in FIG. 1, an electromagnetic-type pump 100 comprises a casing 101 that houses the structural elements of the pump. Electromagnets 110, 120 and an oscillator 130 are housed in a drive chamber 102 inside the casing 101. The electromagnet 110 comprises an electromagnetic coil 111, which is connected to an AC power supply. Like the electromagnet 110, the electromagnet 120 comprises an electromagnetic coil 121, which is connected to the AC power supply. The oscillator 130 comprises permanent magnets 131, 132. An end part of the oscillator 130 on the side opposite the permanent magnets 131, 132 is coupled to a diaphragm part 140. When the electromagnetic coil 111 and the electromagnetic coil 121 are energized, the N pole and S pole positions of the electromagnet 110 and the electromagnet 120 respectively switch, and thereby driving electromagnetic forces are imparted to the oscillator 130. Owing to the attracting and repelling forces between the electromagnetic forces at this time and the permanent magnets 131, 132 on the oscillator 130 side, the oscillator 130 reciprocally oscillates in the first direction X1 and the second direction X2 about a neutral position shown in FIG. 1. The oscillator 130 corresponds to an “oscillator” of the present invention.

The diaphragm part 140 comprises a main-body part 141, a diaphragm 142, a first center disk 150, and a second center disk 160. The main-body part 141 is fixed to the casing 101. The diaphragm 142 is a member composed of a rubber material, which is one example of an elastic material. An outer-edge part 142 a of the diaphragm 142 is immovably attached to the main-body part 141. The diaphragm 142 corresponds to a “diaphragm” of the present invention.

The first center disk 150 and the second center disk 160 are both members composed of a synthetic resin. The first center disk 150 is disposed on the opposite side of the oscillator 130 with the diaphragm 142 interposed therebetween. The second center disk 160 is disposed on the opposite side of the first center disk 150, sandwiching the diaphragm 142. The first center disk 150 and the second center disk 160 are fixed to one another in the state in which a central area of the diaphragm 142 is sandwiched, from both surfaces, in a sheet-thickness direction of the diaphragm 142. The oscillator 130 is coupled to both the first center disk 150 and the second center disk 160. Consequently, the diaphragm 142 is indirectly coupled to the oscillator 130 via the first center disk 150 and the second center disk 160. It is noted that, if the first center disk 150 and the second center disk 160 are fixed to one another, then the oscillator 130 should be fixed to at least one of the first center disk 150 and the second center disk 160. The first center disk 150 and the second center disk 160 herein correspond to a “first center disk” and a “second center disk,” respectively, of the present invention.

A valve case 103 is attached on the opposite side of the oscillator 130, sandwiching the diaphragm part 140 within the casing 101. The valve case 103 comprises a compression chamber 104 and a discharge chamber 105. The compression chamber 104 is provided on the opposite side of the oscillator 130, sandwiching the diaphragm 142. The compression chamber 104 is a space for sucking in air during movement in the first direction X1 (intake direction) of the oscillator 130 and for compressing that air during movement in the second direction X2 (discharge direction) of the oscillator 130. The valve case 103 and the compression chamber 104 herein correspond to a “valve case” and a “compression chamber,” respectively, of the present invention.

An intake valve 170 is provided on a case-wall part 103 a that is interposed between the compression chamber 104 within the valve case 103 and an exterior space 106. The intake valve 170 is configured to open at a pressure-decreased time, which is when the pressure in the compression chamber 104 has decreased, and to open at a pressure-increased time, which is when the pressure in the compression chamber 104 has increased. On the other hand, the discharge chamber 105 is a space for discharging the air that has been compressed by the compression chamber 104. A discharge valve 180 is provided on a case-wall part 103 b, which is interposed between the compression chamber 104 and the discharge chamber 105 of the valve case 103. The discharge valve 180 is configured to close during a pressure-decreased time, which is when the pressure in the compression chamber 104 has decreased, and to open during pressure-increased time, which is when the pressure in the compression chamber 104 has increased.

As shown in FIG. 2, when the oscillator 130 has moved in the first direction X1 owing to the electromagnetic forces generated by the electromagnets 110, 120, the diaphragm 142 is pulled in the first direction X1 via the first center disk 150 and the second center disk 160. Accordingly, the diaphragm 142 elastically deforms such that the volume of the compression chamber 104 increases. At this time, the pressure in the compression chamber 104 falls, the intake valve 170 opens, and the discharge valve 180 closes. Accordingly, air (outside air) from the exterior space 106 is sucked into the compression chamber 104, which is at a relatively low pressure, through the intake valve 170 in the valve-open state.

As shown in FIG. 3, when the oscillator 130 has moved in the second direction X2 owing to the electromagnetic forces generated by the electromagnets 110, 120, the diaphragm 142 is pulled in the second direction X2 via the first center disk 150 and the second center disk 160. Accordingly, the diaphragm 142 elastically deforms such that the volume of the compression chamber 104 decreases. At this time, the pressure in the compression chamber 104 increases, the intake valve 170 closes, and the discharge valve 180 opens. Accordingly, the air in the compression chamber 104 is discharged to the discharge chamber 105 through the discharge valve 180 in the valve-open state.

Here, the details of the diaphragm part 140 having the above-mentioned configuration will be explained, with reference to FIG. 4 to FIG. 7.

As shown in FIG. 4, the diaphragm 142 is configured in a discoidal manner. The diaphragm 142 has an opening 143 in its central area; an opening-edge part 143 a of the opening 143 is sandwiched by the first center disk 150 and the second center disk 160. The first center disk 150 and the second center disk 160 are both configured in a discoidal manner and concentric with the diaphragm 142.

As shown in FIG. 5, the first center disk 150 has a through hole 150 a in its central portion. Likewise, the second center disk 160 has a through hole 160 a in its central portion. An end part of the oscillator 130 on the diaphragm part 140 side comprises a coupling shaft 130 a. The coupling shaft 130 a is screwed into a fixing means 133, such as a nut, in the state in which the coupling shaft 130 a is inserted into both the through hole 150 a of the first center disk 150 and the through hole 160 a of the second center disk 160. As a result, the oscillator 130 is fixed to the diaphragm 142 via the first center disk 150 and the second center disk 160.

The first center disk 150 is disposed opposing an outer surface 144—of the two surfaces of the diaphragm 142—on the compression chamber 104 side of the valve case 103. To clamp and hold the central area of the diaphragm 142 in cooperation with the second center disk 160, the first center disk 150 comprises a discoidal center part 151, which is centered on the through hole 150 a, and a circular-ring shaped outer-circumference part 152, which is located on the outer side in the disk radial direction of the center part 151.

The center part 151 has a first disk contact surface 151 a. The first disk contact surface 151 a is a circular-ring shaped contact surface that makes continuous contact with the outer surface 144 of the diaphragm 142 when the oscillator 130 is in the neutral position. The first disk contact surface 151 a corresponds to a “first disk contact surface” of the present invention. The “neutral position” referred to herein is the position of the oscillator 130 when the diaphragm 142 is in the initial state, in which the diaphragm 142 is not elastically deformed toward either the intake side (the left side in the drawings) or the discharge side (the right side in the drawings), as shown in FIG. 1 and FIG. 5.

The outer-circumference part 152 has a first disk curved surface 152 a. The first disk curved surface 152 a extends from a first circle P1 (hereinbelow, also called an “outer circumference P1 of the first disk contact surface 151 a”), which defines an outer circumference of the first disk contact surface 151 a, while curving outward in the disk-radial direction with a prescribed radius of curvature R and while increasing its spacing from the outer surface 144 of the diaphragm 142; it is formed in a ring shape in the disk circumferential direction. That is, the first circle P1 forms a boundary line that determines a boundary between the first disk contact surface 151 a of the center part 151 and the first disk curved surface 152 a of the outer-circumference part 152. The first disk curved surface 152 a corresponds to a “first disk curved surface” of the present invention.

Like the first center disk 150, the second center disk 160 is disposed opposing an inner surface 145—of the two surfaces of the diaphragm 142—on the oscillator 130 side. To clamp and hold the central area of the diaphragm 142 in cooperation with the first center disk 150, the second center disk 160 comprises a discoidal center part 161, which is centered on the through hole 160 a, and a circular-ring shaped outer-circumference part 162, which is located on the outer side in the disk-radial direction of the center part 161.

The center part 161 has a second disk contact surface 161 a. The second disk contact surface 161 a is a circular-ring shaped contact surface that makes continuous contact with the inner surface 145 of the diaphragm 142 when the oscillator 130 is in the neutral position discussed above. The second disk contact surface 161 a corresponds to a “second disk contact surface” of the present invention.

The outer-circumference part 162 has a second disk curved surface 162 a. The second disk curved surface 162 a extends from a second circle P2 (hereinbelow, also called an “outer circumference P2 of the second disk contact surface 161 a”), which defines an outer circumference of the second disk contact surface 161 a, while curving outward in the disk-radial direction with the abovementioned radius of curvature R (a radius of curvature the same as that of the first disk curved surface 152 a) and while increasing its spacing from the inner surface 145 of the diaphragm 142; it is formed in a ring shape in the disk circumferential direction. That is, the second circle P2 forms a boundary line that determines the boundary between the second disk contact surface 161 a of the center part 161 and the second disk curved surface 162 a of the outer-circumference part 162. The second disk curved surface 162 a corresponds to a “second disk curved surface” of the present invention.

In the diaphragm part 140 of the present embodiment, when the first center disk 150 and the second center disk 160 are compared, it can be seen that these disks are configured such that they have asymmetric shapes. The disk diameter D2 a (outer diameter) of the second center disk 160 is configured such that it is larger than the disk diameter D1 a (outer diameter) of the first center disk 150. In addition, in the diaphragm part 140, the outer diameter D2 b of the second disk contact surface 161 a (i.e., the “outer diameter of the center part 161” or the “diameter of the second circle P2”) of the second center disk 160 is configured such that it is larger than the outer diameter D1 b of the first disk contact surface 151 a (i.e., the “outer diameter of the center part 151” or the “diameter of the first circle P1”) of the first center disk 150. In particular, in the diaphragm part 140, the outer diameter D2 b of the second disk contact surface 161 a is set such that it lies in the range of 1.05-1.30 times the outer diameter D1 b of the first disk contact surface 151 a. That is, with regard to the relationship between the outer diameter D1 b and the outer diameter D2 b, the correlation expression D2 b=1.05×D1 b˜1.30×D1 b holds true. The outer diameter D1 b of the first disk contact surface 151 a and the outer diameter D2 b of the second disk contact surface 161 a are both “clamping diameters” for clamping and holding the outer diameter D2 b of the diaphragm 142.

As shown in FIG. 6, when the oscillator 130 moves in the intake direction (the first direction X1), the outer surface 144 of the diaphragm 142 of the diaphragm part 140 having the above-mentioned configuration is depressed in the first direction X1 by the first center disk 150, and the inner surface 145 is pulled in the first direction X1 by the second center disk 160. At this time, the outer surface 144 of the diaphragm 142 centrally bends at a contact part 144 a, with respect to the outer circumference P1 of the first disk contact surface 151 a, and elastically deforms such that it becomes depressed on the first direction X1 side. In addition, the inner surface 145 of the diaphragm 142 centrally bends at a contact part 145 a, with respect to the outer circumference P2 of the second disk contact surface 161 a, and elastically deforms such that it becomes depressed toward the first direction X1 side. Furthermore, if the oscillator 130 has moved in the first direction X1 until the outer surface 144 of the diaphragm 142 makes contact with the first disk curved surface 152 a of the first center disk 150, then localized bending of the diaphragm 142 is prevented by virtue of the outer surface 144 making surface contact with the first disk curved surface 152 a.

On the other hand, as shown in FIG. 7, when the oscillator 130 moves in the discharge direction (the second direction X2), the inner surface 145 of the diaphragm 142 of the diaphragm part 140 having the above-mentioned configuration is depressed in the second direction X2 by the second center disk 160, and the outer surface 144 is pulled in the second direction X2 by the first center disk 150. At this time, the inner surface 145 of the diaphragm 142 centrally bends at the contact part 145 a, with respect to the outer circumference P2 of the second disk contact surface 161 a, and elastically deforms such that it becomes depressed on the second direction X2 side. In addition, the outer surface 144 of the diaphragm 142 centrally bends at the contact part 144 a, with respect to the outer circumference P1 of the first disk contact surface 151 a, and elastically deforms such that it becomes depressed on the second direction X2 side. Furthermore, if the oscillator 130 has moved in the second direction X2 until the inner surface 145 of the diaphragm 142 makes contact with the second disk curved surface 162 a of the second center disk 160, then localized bending of the diaphragm 142 is prevented by virtue of the inner surface 145 making surface contact with the second disk curved surface 162 a.

According to an electromagnetic-type pump 100 having the above-mentioned configuration, as a result of the reciprocating oscillation of the oscillator 130 in the intake direction and the discharge direction being performed repetitively, a load concentrates at the contact part 144 a on the outer surface 144 of the diaphragm 142 and a load concentrates at the contact part 145 a on the inner surface 145 of the diaphragm 142. At this time, because the outer diameter D1 b of the first disk contact surface 151 a of the first center disk 150 and the outer diameter D2 b of the second disk contact surface 161 a of the second center disk 160 differ, the position in the radial direction of the bent part of the outer surface 144 of the diaphragm 142 and the position in the radial direction of the bent part of the inner surface 145 of the diaphragm 142 differ from one another. Accordingly, it is possible to prevent a local load concentration from arising on the diaphragm 142 during the reciprocating movement of the oscillator 130, and therefore the service life of the diaphragm 142 can be prolonged.

Furthermore, by defining the relationship between the outer diameter D1 b of the first disk contact surface 151 a and the outer diameter D2 b of the second disk contact surface 161 a with the correlation expression of D2 b=1.05×D1 b˜1.30×D1 b, the first center disk 150 located on the compression chamber 104 side of the valve case 103, that is, the center disk located on the outer side, can be made smaller than the second center disk 160 located on the oscillator 130 side and it also becomes possible to keep the size of the second center disk 160 small. As a result, it becomes possible to make the electromagnetic-type pump 100 compact. It is noted that if the outer diameter D2 b is less than 1.05 times the outer diameter D1 b, then the position in the radial direction of the bent part on the outer surface 144 of the diaphragm 142 and the position in the radial direction of the bent part on the inner surface 145 become too close, and consequently the effect of prolonging the service life of the diaphragm 142 becomes small. In addition, if the outer diameter D2 b is greater than 1.30 times the outer diameter D1 b, then the size of the second center disk 160 becomes large compared with the size of the first center disk 150, which is disadvantageous for making the electromagnetic-type pump 100 compact. Accordingly, in the present embodiment, by setting the sizes of the first disk contact surface 151 a and the second disk contact surface 161 a such that they satisfy the above-mentioned correlational expression, the effect of prolonging the service life of the diaphragm 142 and the effect of making the electromagnetic-type pump 100 compact can be achieved simultaneously.

In addition, because the first disk curved surface 152 a of the first center disk 150 and the second disk curved surface 162 a of the second center disk 160 have the same radius of curvature R, the deflection of the diaphragm 142 is the same, i.e., balanced, on the first disk curved surface 152 a side and the second disk curved surface 162 a side. As a result, although the outer surface 144 of the diaphragm 142 makes contact with the first disk curved surface 152 a of the first center disk 150, fatigue of the diaphragm 142 can be prevented from being biased toward either the outer surface 144 or the inner surface 145 when the inner surface 145 of the diaphragm 142 makes contact with the second disk curved surface 162 a of the second center disk 160.

The present invention is not limited to only the representative embodiments mentioned above, and various applications and modifications are conceivable as long as they do not depart from the object of the present invention. For example, each of the following modes in which the above-mentioned embodiments are applied can also be implemented.

In the above-mentioned embodiments, a case is described in which the first disk curved surface 152 a of the first center disk 150 and the second disk curved surface 162 a of the second center disk 160 have the same radius of curvature R; however, a configuration can be utilized in which the radius of curvature of the first disk curved surface 152 a differs from the radius of curvature of the second disk curved surface 162 a.

In the above-mentioned embodiments, a case is described in which the first center disk 150 comprises the outer-circumference part 152 (the first disk curved surface 152 a) and the second center disk 160 comprises the outer-circumference part 162 (the second disk curved surface 162 a); however, it is also possible to omit at least one of the outer-circumference part 152 and the outer-circumference part 162.

In the above-mentioned embodiments, a case is described in which the disk diameter D2 a of the second center disk 160 is larger than the disk diameter D1 a of the first center disk 150; however, the disk diameter D1 a and the disk diameter D2 a may coincide.

In the above-mentioned embodiments, an electromagnetic-type pump 100 is described in which the diaphragm part 140 is coupled to only one-end part of the oscillator 130; however, it is also possible to utilize an electromagnetic-type pump in which the diaphragm part 140 is coupled to both end parts of the oscillator 130.

In the above-mentioned embodiments, an electromagnetic-type pump 100 is described in which the intake movement and the discharge movement of air are performed, which is one type of fluid; however, it is also possible to utilize an electromagnetic-type pump that manipulates gases other than air, liquids, etc. For example, a fuel-cell unit that produces electricity by the chemical reaction of hydrogen and oxygen comprises a gas-supply pump that supplies a gas (municipal gas, LP gas) to a fuel reforming apparatus for extracting hydrogen, and the structure of the above-mentioned electromagnetic-type pump 100 can also be utilized in this gas-supply pump. 

1. A pump comprising: a discoidal diaphragm composed of an elastic material; a first center disk and a second center disk that are both discoidal and concentric with the diaphragm, the first center disk being fixed with respect to the second center disk such that a central area of the diaphragm is interposed between the first center disk and the second center disk; an oscillator coupled to at least one of the first center disk and the second center disk and configured to reciprocally oscillates the diaphragm in an intake direction and a discharge direction about a neutral position; and a valve case disposed on a side of the oscillator that is opposite of the diaphragm, the valve case having a compression chamber for sucking in a fluid during movement in the intake direction of the oscillator and for compressing that fluid during movement in the discharge direction of the oscillator; wherein: the first center disk has a circular-ring shaped first disk contact surface that is disposed opposing an outer surface of the diaphragm that (i) faces towards the compression chamber of the valve case, (ii) makes contact with the outer surface when the oscillator is in the neutral position and (iii) has an outer diameter; the second center disk has a circular-ring shaped second disk contact surface that (i) is disposed opposing an inner surface of the diaphragm that faces towards the oscillator, (ii) makes contact with the inner surface when the oscillator is in the neutral position, and (iii) has an outer diameter set in the range of 1.05-1.30 times the outer diameter of the first disk contact surface; and the diaphragm, the first center disk and the second center disk are configured such that, during reciprocating oscillation in the intake direction and the discharge direction of the oscillator, the diaphragm centrally bends at a contact part within the outer surface of the diaphragm, with respect to an outer circumference of the first disk contact surface of the first center disk, and centrally bends at a contact part within the inner surface of the diaphragm, with respect to an outer circumference of the second disk contact surface of the second center disk.
 2. The pump according to claim 1, wherein: the first center disk has a first disk curved surface that extends from the outer circumference of the first disk contact surface while curving outward in a radial direction of the first center disk with a radius of curvature, the first disk curved surface having a ring shape in a circumferential direction of the first center disk; and the second center disk has a second disk curved surface that extends from the outer circumference of the second disk contact surface while curving outward in a radial direction of the second center disk with the same radius of curvature as that of the first disk curved surface, the second disk curved surface having a ring shape in a circumferential direction of the second center disk.
 3. A pump comprising: an elastic diaphragm; a first center disk, a second center disk fixed with respect to the first center disk such that a central area of the diaphragm is interposed between the first center disk and the second center disk; an electromagnetic oscillator coupled to at least one of the first center disk and the second center disk and configured to reciprocally oscillate the diaphragm about a neutral position; and a valve case disposed such that the diaphragm is interposed between the electromagnetic oscillator and the valve case, the valve case having a compression chamber configured to intake a fluid when the electromagnetic oscillator moves in an intake direction and to compress the fluid when the electromagnetic oscillator moves in a discharge direction; wherein: the first center disk has a first circumference with a first diameter and the second center disk has a second circumference with a second diameter, the first circumference is a radially outermost portion of the first center disk that makes contact with the diaphragm when the diaphragm is located in the neutral position, the second circumference is a radially outermost portion of the second center disk that makes contact with the diaphragm when the diaphragm is located in the neutral position, the second diameter is between 1.05 and 1.30 times greater than the first diameter.
 4. The pump according to claim 3, wherein the diaphragm, the first center disk and the second center disk are configured such that: the diaphragm bends along a first circle adjacent the first circumference of the first center disk when the diaphragm moves in the intake direction, the diaphragm bends along a second circle adjacent the second circumference of the second center disk when the diaphragm moves in the discharge direction, the second circle being larger than the first circle.
 5. The pump according to claim 4, wherein the first center disk is disposed between the diaphragm and the valve case and the second center disk is disposed between the diaphragm and the electromagnetic oscillator.
 6. The pump according to claim 5, wherein: the first center disk has a third circumference with a third diameter and the second center disk has a fourth circumference with a fourth diameter, the third circumference is a radially outermost edge of the first center disk, the fourth circumference is a radially outermost edge of the second center disk, the first center disk curves away from the diaphragm between the first circumference and the third circumference, and the second center disk curves away from the diaphragm between the second circumference and the fourth circumference.
 7. The pump according to claim 6, wherein: the first center disk curves away from the diaphragm between the first circumference and the third circumference with a first radius of curvature, and the second center disk curves away from the diaphragm between the second circumference and the fourth circumference with a second radius of curvature.
 8. The pump according to claim 7, wherein the elastic diaphragm is composed of a rubber material.
 9. The pump according to claim 8, wherein the second circle has a diameter that is between 1.05 and 1.30 times greater than the diameter of the first circle.
 10. The pump according to claim 4, wherein the second circle has a diameter that is between 1.05 and 1.30 times greater than the diameter of the first circle.
 11. The pump according to claim 3, wherein the first center disk is disposed between the diaphragm and the valve case and the second center disk is disposed between the diaphragm and the electromagnetic oscillator.
 12. The pump according to claim 3, wherein: the first center disk has a third circumference with a third diameter and the second center disk has a fourth circumference with a fourth diameter, the third circumference is a radially outermost edge of the first center disk, the fourth circumference is a radially outermost edge of the second center disk, the first center disk curves away from the diaphragm between the first circumference and the third circumference, and the second center disk curves away from the diaphragm between the second circumference and the fourth circumference.
 13. The pump according to claim 12, wherein: the first center disk curves away from the diaphragm between the first circumference and the third circumference with a first radius of curvature, and the second center disk curves away from the diaphragm between the second circumference and the fourth circumference with a second radius of curvature.
 14. The pump according to claim 13, wherein the first radius of curvature is equal to the second radius of curvature. 